What ever happened to humankind’s dominion over the earth? I thought the whole point of civilization was to get rid of the things that hurt, frightened, annoyed, or just creeped us out. Cage the lions, get rid of bats, spray mosquitoes, and swat spiders. Are we sliding backwards, losing our nerve: from “veni, vidi, vici” to “hic sunt dracones”?

Environmentalism in the United States came in two big waves. One was during the era of President Theodore Roosevelt, the advocate of the strenuous life who pushed the creation of the national park system. The second began in 1962 with Rachel Carson’s “Silent Spring,” which led to the first Earth Day and the founding of the Environmental Protection Agency in 1970. While Roosevelt’s conservationism was a celebration of wildlife (the flora and fauna in the woods, not Boston’s hoped-for 4 a.m. closings), the second wave was a reaction to degradation and poisoning. Carson’s book recounted pesticides killing birds and other life. Moreover, it was increasingly obvious that the air had become unbreathable, the water undrinkable, and the soil laden with toxins. The result was a series of major pieces of legislation, including the Clean Air Act, the Clean Water Act, and the Endangered Species Act.

And, of course, since government can never do anything right, all of them failed miserably.

No! In fact, they were a startling success. Indeed, it’s hard to imagine how bleak things were back then and how much better they are today. For example, dense, thick haze once routinely covered many cities. People were often urged not to go outdoors; the air was too hazardous to breathe. Those days are now gone.

Granted, the fixes weren’t easy. Homeowners were outraged when told they couldn’t burn leaves in the fall. New emissions-control systems made cars more expensive. Businesses complained about the costs of scrubbers. Yet their impact has been felt everywhere, from Boston to Los Angeles to London. Remember the storied London fog, whose gloom set the mood for much Victorian literature? It was largely soot and sulfur dioxide from burning coal, making for evocative evenings, yes, but it was also a killer that once took the lives of 12,000 people over a few days. Thanks to environmental controls, the fog is no more. The novelist’s loss is humanity’s gain.

The return of the beasts is also humanity’s gain, a restoration of ecological balance. Their resurgence has been quite intentional, the result of an array of state and federal laws. New England’s landscape, once almost denuded from farming, is now 80 percent forest. The Boston Harbor, mocked as the region’s cesspool, is now swimmable. Raw sewage can no longer be dumped in coastal waters.

No question, many of the complaints about environmental rules are true. They can be arcane, complex, and counterproductive. Impact reviews are too often hijacked by those with parochial interests. Too many regulations are prescriptive (e.g., install this brand of scrubber) rather than results-oriented (e.g., cut particulates by 90 percent). And there are real costs, to businesses and individuals. Fishing restrictions threaten livelihoods. Beachgoers eye piping plovers in their midst and make surly jokes about “tastes like chicken.”

But it’s worth it.

I don’t mean to sound Pollyannaish. Things are far from perfect. Even as we deal with old problems, new crises, such as global climate change, emerge. Yet the history of environmentalism is a fundamentally optimistic story about ourselves and the capacity of government: Despite fits, false starts, blind alleys, and bureaucratic clumsiness, we have the capacity to improve things. It’s not a matter of whether we can. It’s a matter of politics, a matter of whether we will.